Self-restraining pipe joints refer to pipe joints that do not require any external support for joint restraint. In applications where a fluid such as water for fire mains is held under high pressure, self-restraining pipe joints typically rely on pipe joint gaskets that include anti-slip segments for preventing the separation of the interconnected pipes forming the joint. Exemplary gaskets are described in U.S. Pat. Nos. 5,295,697, 5,464,228 and 8,490,273 in which a rubber gasket, serving as a fluid seal, includes toothed metal segments spaced uniformly around its inner perimeter. The toothed segments bite into the outer surface of the spigot of the inserted pipe and prevent withdrawal of the inserted pipe from a bell end of the other pipe. The segments pivot about a retainer bead in the bell end of the other pipe to allow the spigot end to be inserted into the bell end of the other pipe while preventing withdrawal of the inserted pipe under fluid pressure conditions.
During fluid pressurization of the interconnected pipes, axial thrust force is generated by the resulting hydrostatic pressure, which causes the interconnected pipes to want to separate thereby undoing the pipe joint. A shortcoming of current gaskets which contain anti-slip segments for use in self-restraining pipe joints is that the axial thrust force generated by pipe pressurization increases with the square of the outer diameter of the spigot of the inserted pipe, while the available pipe surface for engagement by the anti-slip segments only increases proportionally with the outer diameter of the spigot. This relationship limits the use of such gaskets in self-restraining pipe joints formed between pipes with relatively large diameters since the lack of available pipe surface area can provide for insufficient engagement the anti-slip segments with the pipe. On the smaller end of the scale, the tight radius of curvature on small diameter pipes limits the contact area of the anti-slip segments with the round, outer surface of the spigot. Accordingly, there is a need for a pipe gasket having anti-slip segments that maximize their engagement with an outer surface area of a pipe. There is also a need for a pipe gasket that improves dissipation of the radial forces imparted to the pipe by anti-slip segments during pressurization so as to decrease the likelihood that the segments over penetrate the pipe and cause a catastrophic failure of the pipe joint.